Fix windows packaging

cmake/modules/NSIS.template.in

@@ -1,6 +1,6 @@
 ;ownCloud installer script.
 
-!define APPLICATION_SHORTNAME "@APPLICATION_SHORTNAME@"
+!define APPLICATION_SHORTNAME "@APPLICATION_EXECUTABLE@"
 !define APPLICATION_NAME "@APPLICATION_NAME@"
 !define APPLICATION_VENDOR "@APPLICATION_VENDOR@"
 !define APPLICATION_EXECUTABLE "@APPLICATION_EXECUTABLE@.exe"